Go to the setup Menu
Set up System, Unit, Position Format & Time
Tracks: turn on/off current track
Map: change map settings.
Position Format (including Map Datum) should be set to the communication format for the incident.
For Latitude and Longitude options are:
Degrees Minutes Seconds (DMS)
Decimal Minutes (DM)
Decimal Degrees (DD) (rarely used)
I also included a file of "GPS Pocket Guide GPA map 62" this is in power point.
Hope this helps